I thought Thom gave a rather informed response earlier regarding how AutoCAD works. Not much different than SketchUp, except AutoCAD breaks things down to a far greater degree of detail. AutoCAD’s “circles” are not really different than SketchUp. In fact there are nothing but straight lines in NURBS. I personally regard SketchUp as a first rate CAD package. You don’t … why?
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I drew a circle is SketchUp, and changed the number of sides from 24 to 8. I then exported the circle as a DWG. When I imported it into CorelDRAW, this is what I got.
In CorelDRAW I could snap to the midpoint, or any part of the sides. The vertices were identified as Nodes, and could be snapped to. What was really interesting is that CorelDRAW recognized the circle, and I could snap to any point on the circle.
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It summarizes nothing of what you understand. Only you can do that. Unless I am mistaken and ‘copilot’ is how you refer to yourself in 3rd person.
¯_(ツ)_/¯
We are doomed.
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Hi. Thanks for the reply
If there was a plugin that took arcs and circles and made them true arcs and circles, not faceted, it would be great for laser cutting etc on CNC machines.
I save all my designs as suggested on the forum as 3d drawings but often the laser cutters complain about having to redraw. This is especially on small diameters. My diameters are from 3mm to 10mm usually.
If a plugin sorted those out it would be very time saving.
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When you model are you treating mm as m? Those are very small faces and SKP struggles with that.
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I have tried scaling up x10 and then reducing but doesn’t seem to help.
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What about if you draw it in meters, export as 3d DWG (or use OpenCutList?) and have your laser guys scale it back down to millimeters?
Thanks Mike. I will try that. I always saved as 3d dxf but will try the meter scale option now.
Thanks for the suggestion
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IMO you had both Edges and Faces checked when exporting. The 8-sided thingy i the “face”.
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I merely exported the model as a DWG. The 8 sided polygon is SketchUp’s circle. The circle that CorelDRAW created is the result of information about the SketchUp circle that was included in the export process. So one might ask, if SketchUp has the necessary information for creating an actual circle entity, might it someday be possible to do exactly what CorelDRAW can do? While this may have no value to me personally, I’m sure there are many CAD technicians who might find this essential in their work.
Could be that CorelDraw added info. Pi?
It has radius. It can’t draw circles. You need to ‘add’ that in.
Here is a video of an extension that I made for SketchUp that can draw a circle svg.
No it is not. It is the circle’s FACE. I followed your example, drew a circle in SketchUp, set its segments to 8 and exported to DWG with both edges and faces selected. The edges exported as a circle and the face became a 8-sided polyface. This was all as expected. Image from DWG TrueView.
You have not taken the time to learn how to export 2d circles from SketchUp. There are many tutorials you can search for here on the forum. You are getting the true 2D circle and the faceted face because you are asking for them both to be exported in the SketchUp export options. Turn off the face export. In SketchUp as in life, you get what you ask for.
At the risk of repeating myself, what are you looking for, here? Do you want to understand how SketchUp does what it does? Are you asking SketchUp to work like CorelDraw?
If your Feature Request is “Make SketchUp model with true curves” you have heard that, foundationally, that is not how SketchUp works. It is not impossible to add that functionality, but far from trivial.
If your goal is to understand how it does what it does, you have had some very knowledgable users attempt to help you out.
Posting AI descriptions of circles and examples of using SketchUp incorrectly and saying it should be different are not moving this conversation forward.
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I’m not sure of how I was using SketchUp incorrectly. All I did was a simple export of a simple model. The imported result in CorelDRAW clearly demonstrates that the necessary information to draw a circle is already in SketchUp. I thoroughly appreciate that anything drawn by SketchUp is a series of connected line segments. I also appreciate that creating lines that are tangent to a circle, requires a precise mathematical calculation, since an actual circle is only theoretical, otherwise you have an approximation.
My simple question has never been answered. That was, considering the current underlying code, would it be a major undertaking to have SketchUp create circles, as opposed to polygons? What I find particularly interesting is that in the Entity Info of a circle, the actual circumference is given. This can only be done by using a code object that does the necessary calculation, as opposed to stating the length of the polygon perimeter. For that matter, SketchUp might consider listing a circle’s area, in addition to the area of the face.
If you think I have no understanding of how SketchUp works, let me know, and I won’t bother you any more.
Hi @JamesClark, please read the previous post carefully. Specifically the part that says:
Additionally, please read this part of the thread:
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I see. SketchUp essentially works with segments. Arcs and circles are true entities that retain the specific information of arcs and circles, associated with a collection of segments.
In the case of multiple modeling operations, these entities may be lost, replaced by segments. However, in elementary operations (extrusion, cutting with a line…), these arc and circle entities are still retained.
Do you have a case in one of your files where in SketchUp you always display these entities (confirmed by entity info) and the result is segmented when sending to a CNC machine?
If so, this requires writing an export script with rigorous data management and conversion.
This is already the case. In SketchUp, there is a specific entity with arcs and circles, with this information, which is preserved in the model, as long as possible:
If, for example, SketchUp would simplify certain calculations (perimeter, area, etc.) on arcs (I don’t know, it’s a hypothesis) by interpreting them as polygons, nothing would prevent it from being improved or producing a script that calculates more precisely by retrieving the information from the entity.
[EDIT:] Yes, the result is not the same depending on the segmentation, but this is normal and logical.
When setting the number of segments of an arc or a circle, it is not easy to imagine something automatic, with automatic quality adaptation, because this generates geometry, when the circle is extruded for example, and it is not easy to manage in the algorithms and in the user experience.
by James’s logic a point cloud would be 0-dimensional
Don’t poke the bear!
And where have I seen that happen also, lately?
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